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[174.3.196.123]) by smtp.gmail.com with ESMTPSA id x27sm97528849pfe.178.2019.01.02.11.07.41 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 02 Jan 2019 11:07:41 -0800 (PST) Received: from jgg by mlx.ziepe.ca with local (Exim 4.90_1) (envelope-from ) id 1gelrg-0004Nj-PO; Wed, 02 Jan 2019 12:07:40 -0700 Date: Wed, 2 Jan 2019 12:07:40 -0700 From: Jason Gunthorpe To: Leon Romanovsky Cc: YueHaibing , dennis.dalessandro@intel.com, mike.marciniszyn@intel.com, dledford@redhat.com, linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org Subject: Re: [PATCH -next] IB/qib: Add missing err handle for qib_user_sdma_rb_insert Message-ID: <20190102190740.GH26211@ziepe.ca> References: <20181221021938.13784-1-yuehaibing@huawei.com> <20190102171224.GA26765@ziepe.ca> <20190102184050.GI5424@mtr-leonro.mtl.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190102184050.GI5424@mtr-leonro.mtl.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 02, 2019 at 08:40:50PM +0200, Leon Romanovsky wrote: > On Wed, Jan 02, 2019 at 10:12:24AM -0700, Jason Gunthorpe wrote: > > On Fri, Dec 21, 2018 at 10:19:38AM +0800, YueHaibing wrote: > > > It should goto err handle if qib_user_sdma_rb_insert fails, > > > other than success return. > > > > > > Fixes: 67810e8c3c01 ("RDMA/qib: Remove all occurrences of BUG_ON()") > > > Signed-off-by: YueHaibing > > > drivers/infiniband/hw/qib/qib_user_sdma.c | 2 ++ > > > 1 file changed, 2 insertions(+) > > > > > > diff --git a/drivers/infiniband/hw/qib/qib_user_sdma.c b/drivers/infiniband/hw/qib/qib_user_sdma.c > > > index 31c523b..e87c0a7 100644 > > > +++ b/drivers/infiniband/hw/qib/qib_user_sdma.c > > > @@ -237,6 +237,8 @@ qib_user_sdma_queue_create(struct device *dev, int unit, int ctxt, int sctxt) > > > > > > ret = qib_user_sdma_rb_insert(&qib_user_sdma_rb_root, > > > sdma_rb_node); > > > + if (ret == 0) > > > + goto err_rb; > > > } > > > > This doesn't look right, what about undoing the kmalloc directly > > above? > > Back then, I came to conclusion that qib_user_sdma_rb_insert() never > returns 0. Otherwise, Dennis would see that BUG_ON() for a long time > ago. It fails if the index is in the RB tree, which would indicate a programming bug. The way to replace the BUG_ON is something like: if (WARN_ON(ret == 0)) { kfree() goto err_rb; } Jason